Metal bellows are used in various technical domains as a component of variable length, for example, when necessary to equalize length in lines or coupling connections for flowable media. Metal bellows are also common in hydraulic accumulators as a movable separating element between the gas side and fluid side. Especially in applications in which relatively extensive movements take place during expansion and contraction of the bellows, it is important for the service life of the bellows that the respective end of the bellows moved along a housing wall in operation is reliably guided.
As shown from EP 1 052 412 A2, the prior art with respect to the present invention includes providing a guiding element on the movable end of the bellows. In the known solution the movable end body of the bellows is a sealing body for a hydraulic accumulator. Within the accumulator housing, the bellows separates the gas side from the fluid side. The guiding element is a guide ring surrounding the outside periphery of the sealing body and forming an external sliding surface movable along the inside wall of the accumulator housing.
This known solution is disadvantageous in several respects. On the one hand, production is complex because the guide ring is L-shaped in cross section and is fixed on the outer periphery of the sealing body by welding. On the other hand, corresponding production efforts due to the guide ring have to be provided with a series of openings allowing passage of media during the axial movements of the sealing body.